Metering Standards & Protocols

A variety of standards is employed along the smart metering data flow chain. These drive how meters operate and communicate among each other (also referred to as meter bus systems), to how they transfer data to the gateway, and then onwards from the gateway to the central server and finally the transfer to the EDMS. Below is an overview of standards and protocols that can be employed at every step of the data transfer chain.

 

Meter to meter / gateway protocols

Meters communicate mainly with the gateway, but it is possible that meters communicate among each other to relay information. In mesh networks, each meter can both receive and transmit data to other meters as well as a central receiver unit. This networks are sometimes also called “self-healing”, in the sense that a malfunction of an individual meter doesn’t impede the data transmission from other meters (each meter being able to transmit data from all other meters to the central receiver or gateway)

A distinction has to be made between the physical layer and the network and application layers:

  • Physical layer: the way the different nodes are physically connected to one another; it generally falls into two categories: wired and wireless connections
  • Network layer: specifies how different nodes in the network identify each other and route data
  • Application layer: specifies how the data is handled between nodes on the network

 

Physical layer
Wireline connection technologies
TechnologyRangeData RateDescriptionUsed by
LAN (Ethernet)HighHigh to Very HighInterconnects devices using standard Cat 5 networking cables.Business Networks
PLC (Powerline)Low to HighHighElectronic data is transmitted over power lines via specialised devices that typically provide Ethernet or Wi-Fi connectivity. It is a cheap way to avoid having to run new cabling through the building but relies on the quality of the electricity circuit.Home Network
2-Wire SerialLow to MediumLow to MediumConnection between devices using a serial link. Also called 2 wire connection.M-Bus, Sensor to Meter connections
RS-232Low to MediumLow to MediumSerial connection typically used between computers and peripherals.
ARCnetLowLowIndustrial control
Twisted PairLow to MediumLow to Medium
PowerlineLow to MediumLow to MediumUsing electricity supply wiring with frequency modulation to transmit network signals.
Fiber opticsHighHigh

 

Wireless connection technologies
TechnologyFrequencyPowerRangeData RateDescriptionUsed by
Wifi2,4 GHz or 5 GHzHighMediumMediumAllows an electronic device to exchange data or connect to the internet wirelessly using radio wavesBlinkmeter
433 MHz433 MHzMediumMediumHighSmall electronic circuit used to transmit and/or receive radio signals on one of a number of carrier frequenciesOrsis , Data Loggers
866 MHz (Europe only)866 MHzMediumMediumHighSame as 433MHz on different frequency, limited to Europe for legal reasonsData Loggers
Zigbee (IEEE 802.15)2.8 GHzLowHighLowHigh level communication protocols used to create personal area networks built from small, low-power digital radiosIoT, sensors
Bluetooth2.44 GHzLowLowLowWireless technology standard for exchanging data over short distancesMobile
Z-Wave868, 900, 908, 916, 920, 922 MHzLow30 meters9.6 or 40 kbpsLow power radio protocol designed for home automationIoT, sensors
KNX-RF868 MHzMediumMediumHighLow power radio protocol used by the KNX protocolIoT, sensors
Infrared33-40, 50-60 kHzLowLow (line of sight required)LowShort distance wireless technology used in home electronicsRemote controls

 

Application layer

Examples for application layer protocols:

ProtocolData link layerDescription
ModBusModBusHigh level protocol designed to exchange sensor data over a network.
ModBus over TCPTCP/IPVersion of ModBus that works on top of TCP/IP.
MQTTTCP/IPLightweight publish / subscribe protocol designed for low power devices.
MQTT-SNTCP/IPSimplified version of MQTT for sensor networks.
M-BusM-BusProtocol designed the support exchange of sensor data with very low power devices. This can be used to connect sensors to meters but also meters to concentrators.
Z-WaveZ-WaveZ-Wave home automation protocol.
0MQ (Zero MQ)TCP/IP, IDP, MulticastDistributed lightweight message queue protocol.
BACnetBACnet, BACnet/IP
KNXKNX
LonWorks (ISO/IEC 14908)LonWorks

 

Gateway to server

From the gateway to the server, the communication is either based on mobile communication technology or standard internet protocols (via a wireline broadband connection, ie Ethernet). There are also a number of emerging long range WAN (Wide Area Network) technologies that are based on a limited number of network stations across a defined geographical area (for instance a city).

TypeCollection FrequencyData FrequencyCostsProsCons
Wireless (GPRS, Radio)Daily15min-30minDepending on provider, e.g. £10/meter/yreasy to configurehigh ongoing cost
Wired5sec-5min1min-5min0low cost, high frequencyrequires internet connectivity

 

Server to EDMS

From the server the communication is typically fully based on standard internet protocols (with the server or servers itself being hosted in a datacenter with full broadband connection).

ProtocolEncrypted connectionAuthentication optionsGuaranteed deliveryHigh frequency updatesSetup complexity
HTTPHTTPS onlyOptional: HTTP Basic Auth, SSL Mutual Auth, WS-SecurityYesYesLow
FTPSFTP or FTPS onlyPasswordYesNoMedium
EmailNoNoneNoNoLow
UDPNoNoneNoYesLow
MQTTOptionalOptionalOptionalYesMedium